Rotary engine.



J. A. U LBERG.

ROTARY ENGINE APPLICATION FILED APR. 6. I917. Ji,%,2i@&. Fatentafl NOV 191?.

2 SHEETS-SHEET lv J. A. ULBERG,

ROTARY ENGENEP APPLICATION FILED APR. 6. i917.

3*atentefi Nov. 27/, 191?.

2 SHEETSSHEET 2.

enn owners, or mor NORTH DAKOTA.

LROTABY ENGINE.

Specification of Letters Patent.

Patented not. 2?, rain.

Application filed April 6, 1917. Serial No. 160,270.

To all whom it may concern:

Be it known that I, J OHN A. ULBERG, a citizen of the United States, residin at Mott, in the county of .Hettinger and State of North Dakota, have invented new and useful Improvements in Rotary Engines, of which the following is a specification.

: My invention relates to that class of rotary engines in which the piston'head runs in an annular groove or working chamber in the engine casing and is mounted on and carried by a disk fitted within the casing and keyed upon an engine shaft rotatably mounted in the casing. Under my invention the steam inlet port is located in the casing on the opposite side of the piston disk from that on which the steam supply duct or pipe for said port enters the casing, the arrangement being such that the steam from said duct must pass through the piston disk, beforeit can reach its inlet port. By forming in the disk a series of slots or openings extending in a circular path concentric with the shaft on which the disk is mounted, and registering with the steam supply duct, the

steam from the latter will discharge through said openings in the disk duringthe revolution of the latter and can thence be led to the steam inlet port beyond. By making the series of openings-inthev disk less than a complete circle-or in other words making it a segment of a circle only in extentthere will be an imperforate space in the disk between the ends of this segment through whichthe steam from the duct cannot pass, and this imperforate space acts as a steam cut-01f, the engine working by steam'expansion until the completion of the revolution of the piston disk, the cut-01f of the steam taking place sooner or later in the revolution of the disk, according to the dimensions of the segment. Itis this feature which mainly characterizesmy invention.

This and other features of my invention can,however, best be explained and understood in'connection with the accompanying drawings forming part ofthis specification in which Figure 1 is a front elevation of a high pressure motor embodying my improvements. 7

Fig. 2 is a side elevation of the same.

Fig. 3 isa side elevation of the inner face of one of the halves of the casing-theother half having precisely the same structure.

Fig. 4 is a section on-line H Fig.2.

Fig. 5 is a section online 5-5 Fig. 4:.

Figs. 6 and 8 are right and left side ele vations of the piston disk.

Fig. 7is a front elevation of the same. Fig. 9 is a sectional view of a modified formofgroove and piston head.

Figs. 10, 11 are views of. a modification inthe piston head packing arrangement.

. The casing of the engine consists of two symmetrical halves or sections a, between which, at or near their outer edges, a layer offiber or other suitable packing is interposed. The casing sections are drawn together by bolts, making a steam tight joint; andare provided with axial bearings, and suitable stufling boxes 9, for'the engine shaft f as shown. a

The two parts a of the casing, are solid blocks, the parallel meeting faces of which are recessed, as shown in Fig. 4, to receive the hub and body of the piston disk 9' which fit snugly between them, there also being formed in their meeting faces the annular groor e or working chamber 6 to receive the piston head 7a which is formed on or secured to the disk 0'. The meetingfaces of the two parts a of the casing are alike and match one another; the inner face of one of them is shown in side elevation in Fig. 3. The annularworking chamber e may be of any suitable shape in cross section; in Fig. 4 it has a square cross-section, and in Fig. 9 it is represented as oblong in cross section with parallel top and bottom and rounded ends. The piston head is of course has a cross section corresponding to that of the annular working chamber. Any suitable packing can be employed to make. a steam tight joint between the piston head and the walls of the working chamber. In Fig. 5, thereis shown for this purpose U-shaped piston packing rings,=.under which leads a-duct i from the steam face ofthe piston head, so that steam may be admitted under the rings for the purpose ofexpanding them against the walls of the working chamber. In the place of U-shaped rings, keyed. side-wing pins 0 may be used as shown in Figs. 10 and 11. In the sides of the casing a are steam inlets c which are directly opposite one another at the point where they open into the working chamber 6, as shown in Fig.5, and associated with the same are swinging abutments 6, one for each steam inlet, pivoted on pins I)" in recesses 5 in the side walls of the-working chamber. When dropped as some little distance shown in Fig. 5 they fit closely against the piston disk on opposite sides of the same to form a steam tight abutment; when folded back they are received in the recesses b and ofier no obstruction to the passage of the. piston head is. The steam inlets 0 enter the working chamber at the points where the recesses b are located, and therefore they are closed by the abutments I) when the latter are folded back into the recesses, and are there held by the piston head. As soon however as the piston head clears or passes beyond the abutments the latter are free to swing back into working position, and are thus moved by the pressure of the steam issuing from the inlets 0.

In the walls of the casing are exhaust openings which open into the working chamber e, at a suitable distance in rear of the swinging abutments b; one of these exhaust openings is shown at n Fig. 3. The front end of the piston head 7c or that end which first meets the abutments bis tapered or wedge-shaped, as shown in Fig. 5, to enter between the swing abutments, and gradually fold them back. Inasmuch as the piston head, after closing the exhaust alias still to'travel before reaching the swinging abutments, the air compressed between the latter and the advancing piston head will tend to start the fold ing back movement of the abutments before they are reached by the piston-head, thus reducing materially the shock of contact between the two, and rendering the action ex tremely gentle.

In that portion of the piston disk, which does not enter the working chamber, and is located between the snug fitting interior 0pposite faces of the two parts a of the casing-- in this instance the portion of the disk between its hub and the piston head near its periphery-are formed two series Z, Z of closely assembled holes or oblong curved slots or openings, extending part way around the disk in a circular path concentric with one another and with the axis of revolution of the disk. In eachhalf or part of the casing a are two ducts p, p'i(Fig. 3) which extend through from the inner to the outer face of the sameand are located so that the ducts. p, p, in the one part a, will be on the axial prolongation of the ducts p, p, respectively in the other part a, and so that the ducts 79, 29, shall register from opposite sides of the disk with the outer segmental row Z of openings through the disk which intervenes between them, and the ducts p, shall similarly register with the inner and smaller concentric segmental row Z of openings through the disk. The duct 79 in the right hand part a of the casing communicates with a steam supply pipe 72.; and from the outer end of the corresponding duct 7) in the left hand part of the casing leads a continuation it of the same to the steam inlet port 0 in said left hand part of the casing. Similarly,"the duct 27" in the left hand part of easing a in Fig. 1 communicates with a steam supply pipe h;

and from the outer end of the corresponding duct 7) in the right hand part of the casing leadsa continua tion 7:. of the same-to the steam inlet ports a in said right hand part of the casing.

Under this arrangement it 'will be seen that so longas that portion ofthe .piston disk in which the segmental rows of open ings Z, Z are formed isfpassing the ducts p, p steam will be supplied to the steam inlets c; and on the otherhandthe steam will be cut off from those inlets whenever andso long as the imperforateportion of the disk. is passing said' ducts-the travel of the steam through the casing being from right to left in the case of the ducts p, and from left to right in the'case'ofv the ducts p. The segmental rows. or series of openings Z,.Z are so located and proportioned as to meet and quit their respective ducts p, 9 simultaneously. They are positioned so that they meet their respective ducts just-as the piston head 76 clears the swing abutments b; and they quit or pass beyond their re spective ducts sooner or tion of the piston disk according to their extent or length, which will be proportionate .to the cut-off desired -the engineduring the remainder of the revolution ofthe piston later in the revoludisk working expansively aswill be underto the increase or decrease in'the distance which separatessaid terminals.. Holes m,Figs. 6. and :8, are formed in the piston disk to permit steam to-passfroni one side of the disk-to the other and equalize pressure. The grease cups d (Fig. A) are provided for thejournals of the swing abutments b; by removingthe plugs; access can be had to the pivot pins 6 of saidabutments. w

Having now described my improvements and the best way now known to me of carry? ing the same into practical effect, I state in conclusion that I do .not restrict my claim to the structural details hereinbefore shown tion since manifestly the same canvbe considerably varied without departure from the spirit of the invention: But what I claim and desire to secure by Letters Patent is as follows:

1. In a rotary engine the combination of an engine shaft; a piston disk mounted thereon and revolving therewith and formed with two concentric lines of openings through it, extending in a circular path, struck from the axis of revolution of the disk as a center, part way only around the disk, leaving between the opposed terminals of the two lines of openings an imperforate portion of the disk to serve as a steam cutolf; a piston head mounted on said piston disk; a sectional casing formed with'bearings to receive the engine shaft and having the interior opposite faces of the sections of which it is composed recessed to contain and snugly fit that portion of the disk in which the two concentric lines of openings are located, and with an annular groove forming an annular working chamber in which the piston head which is mounted on the disk is received and can travel; two steam inlets extending from opposite sides of the casing and opening into the Working chamber at directly opposite points in the side walls of the same; two sectional steam supply ducts, one for each steam inlet, each of which ducts extends through the sectional casing from the side opposite that on which its steam inlet is located, to the other side of the casing where it connects with its steam inlet, said supply ducts registering the one with one of the lines of concentric openings in the disk, the other with the other line of said openings, said openings Copies of this patent may be obtained for five cents each, by addressing the serving to maintain communication between the sections of each supply duct and the arrangement being such that during the revolution of the disk so long as the steam supply ducts are in register with their re spective lines of openings in the disk steam will pass through the said steam supply ducts to their respective steam inlets, but when the line of openings has passed and the imperforate portion of the disk is interposed, the steam supply through the ducts to their respective steam inlets will thereby be cut-off, substantially as and for the purposes hereinbefore set forth.

2. The combination with the elements of the combination specified in claim 1, of swing abutments pivoted in the sides of the annular working chamber and adapted when unfolded, to close against that portion of the piston disk which is received in the working chamber, from opposite sides of said disk, and to serve as an abutment, and recesses in the sides of the working chamber to contain the swing abutments when folded back to permit the passage of the piston head, the steam inlets entering said recesses so as to be back of the swing abutments when the latter are contained therein, and the arrangement being such that the swing abutments shall be automatically folded back into their recesses by the piston head, and moved in the contrary direction to form an abutment by the action upon them of the steam issuing from the inlets substantially as and for the purposes hereinbefore set forth.

JOHN A. ULBERG.

Commissioner of Patents.

Washington, D. G. 

